Implantable device fastening system and methods of use

ABSTRACT

A surgical fastening system for implantable devices is disclosed. The implantable device may contain a plurality of fasteners in pre-deployment position, may have a housing fitted over or around it which contains a plurality of fasteners in pre-deployment position, or may be a part of a two-part system into which it fits. Accordingly, the present invention also encompasses a deployment system or tool that optionally positions the implantable device, and which causes the fasteners to move into post-deployment position. The fasteners may be staples, metal loops, coils, springs or hooks formed of biocompatible materials, including shape memory alloys such as NiTi.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.10/562,954 now U.S. Pat. No. 7,762,998, having a 35 U.S.C. §371 date ofDec. 30, 2005 as a National stage application of PCT/US05/01958, filedJan. 21, 2005, which claims priority to U.S. Provisional Application No.60/538,674 filed Jan. 23, 2004, each of which is incorporated herein byreference in its entirety. The present application is also acontinuation-in-part of U.S. application Ser. No. 10/562,964, having a35 U.S.C. §371 date of Dec. 30, 2005 as a National stage application ofPCT/US04/30053, filed Sep. 15, 2004, which claims priority to U.S.Provisional Application No. 60/503,074 filed Sep. 15, 2003 and to U.S.Provisional Application No. 60/538,674 filed Jan. 23, 2004, each ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the fields of implantable medicaldevices and surgical instruments and fasteners. The present inventionencompasses methods of fastening devices or implants in surgicalprocedures and the surgical fasteners and instruments used in theprocess.

BACKGROUND OF THE INVENTION

Surgical fasteners such as staples, clips, clamps, bands, tacks, orother wound or incision closure devices are commonly used in surgicalprocedures to allow a surgeon to fasten, secure and/or repair bodytissue. Examples of surgical fasteners are given in U.S. Pat. Nos.4,994,073 or 4,950,284 or 4,934,364 and 4,932,960.

Surgical fasteners have been used in surgical procedures to eliminatethe need for suturing, which is both time consuming and inconvenient. Inthese applications the surgeon often uses a fastener implanting deviceloaded with one or more surgical fasteners to accomplish in a fewseconds what would have taken many minutes to perform by suturing. Thisreduction in operating time reduces blood loss and trauma to thepatient.

Typically, such fastening systems have been used mainly for the closureof incisions or wounds, or to fasten tissues together. A surgicalfastening system that could be used with a number of types ofimplantable devices would be beneficial for surgeons. Currently,surgical devices that incorporate fastening systems often use extremelyspecialized systems that may be unnecessarily complicated and areunsuitable for adaptation to other applications. As a result, themajority of implantable devices are secured with sutures. For example,when inserting a gastric band and the associated access port, the portis sutured into place with 4 to 5 sutures against the rectus musclesheath. Such placement of the sutures is often challenging because theports are placed below several inches of fat, and suturing the portoften takes as long as placing the band itself. An improved fasteningsystem would allow easy, one-step attachment with security equivalent tothe sutured device.

The present invention overcomes such problems in the art.

SUMMARY OF THE INVENTION

The present invention encompasses surgical fastening systems wherein animplantable device either contains a plurality of fasteners inpre-deployment position, or wherein an implantable device may have ahousing fitted over the device, wherein the housing contains a pluralityof fasteners in pre-deployment position. Accordingly, the presentinvention also encompasses a deployment system that optionally positionsthe implantable device, and which causes the fasteners to move intopost-deployment position.

Features and advantages of the present invention will become appreciatedas the same become better understood with reference to thespecification, claims, and appended drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will be morefully understood by reference to the following description and annexeddrawings, in which:

FIG. 1 is a top perspective view of a radial pivot fastener with staplesin pre-deployment positions;

FIG. 2 shows top and bottom perspective views of the radial pivotfastener of FIG. 1 with staples in deployed positions; the top viewshows the staples locked-out in the deployed position, while the bottomview shows the staples nested against the bottom of port which is thus“sandwiched” between a housing ring and the staples;

FIG. 3 is a detail elevation view of the radial pivot fastener of FIG. 1with staples in pre-deployment position;

FIG. 4 is a detail elevation view of the radial pivot fastener of FIG. 2with staples in deployment position;

FIG. 5 is an elevation view of a delivery system;

FIG. 6 is a cutaway view of the delivery system shown in FIG. 5 and aport fastener;

FIG. 7 is a detail cutaway elevation view of the distal end of thedelivery system of FIG. 6 and a port fastener in pre-deploymentposition;

FIG. 8 is a detail cutaway elevation view of the distal end of thedelivery system of FIG. 6 and a port fastener in deployment position;

FIG. 9 is an elevation view of a pencil grip handle configuration for adelivery system;

FIG. 10 is a detail cutaway elevation view of the handle of the deliverysystem of FIG. 9 shown in a starting position;

FIG. 11 is a detail cutaway elevation view of the handle of the deliverysystem of FIG. 9 shown in a fired position;

FIG. 12 is an elevation view of a pistol grip handle configuration for adelivery system;

FIG. 13 is a detail elevation view of the handle of the delivery systemof FIG. 12 shown in a starting position;

FIG. 14 is a detail elevation view of the handle of the delivery systemof FIG. 12 shown in a fired position;

FIG. 15 is an elevation view of another pistol grip handle configurationfor a delivery system;

FIG. 16 is a detail view of the gear train mechanism of the deliverysystem of FIG. 15;

FIG. 17 is a detail cutaway elevation view of the delivery system ofFIG. 15 shown in a starting position;

FIG. 18 is a detail cutaway elevation view of the delivery system ofFIG. 15 shown in a full spring recoil position;

FIG. 19 is a detail cutaway elevation view of the delivery system ofFIG. 15 shown in a fired position;

FIG. 20 is an elevation view of a continuous NiTi wire form fastener inpre-deployment position;

FIG. 21 is an elevation view of the continuous NiTi wire form fastenerof FIG. 20 in post-deployment position;

FIG. 22 is a bottom elevation view of a straight leg, blunt tipcontinuous wire form fastener;

FIG. 23 is a bottom elevation view of a curved leg, blunt tip continuouswire form fastener;

FIG. 24 is a bottom elevation view of a molded tip continuous wire formfastener;

FIG. 25 is an elevation view of a continuous NiTi wire form fastenerwith ground tips in post-deployment external position;

FIG. 26 is an elevation view of a continuous NiTi wire form fastenerwith ground tips in post-deployment internal position;

FIG. 27 is a bottom elevation view of the continuous NiTi wire formfastener with ground tips of FIG. 26 in post-deployment internalposition;

FIG. 28 is an elevation view of a radial slide fastener with straightlegs and a staple guide;

FIG. 29 is an elevation view of the radial slide fastener of FIG. 28;

FIG. 30 is an elevation view of a radial slide fastener with curvedlegs;

FIG. 31 is an elevation view of a two-part fastening system beforeinstallation;

FIG. 32 is an elevation view of the two-part fastening system of FIG. 31after installation;

FIG. 33 is an elevation view of another two-part fastening system beforeinstallation;

FIG. 34 is an elevation view of the two-part fastening system of FIG. 33after installation;

FIG. 35 is an elevation view of a stand-alone fastener incorporated intoa device;

FIG. 36 is an elevation view of another stand-alone fastenerincorporated into a device;

FIG. 37 is an elevation view of another stand-alone fastenerincorporated into a device;

FIG. 38 is an elevation view of another stand-alone fastenerincorporated into a device;

FIG. 39 is an elevation view of another stand-alone fastenerincorporated into an injection port in a pre-installation position;

FIG. 40 is an elevation view of the stand-alone fastener of FIG. 39 in apost-installation position;

FIG. 41 is an elevation view of a helical coil fastener;

FIG. 42 is an elevation view of another helical coil fastener;

FIG. 43 is a top view of a horizontal coil fastening system base;

FIG. 44 is a side view of the horizontal coil fastening system base ofFIG. 43;

FIG. 45 is a bottom view of the horizontal coil fastening system base ofFIG. 43;

FIG. 46 is an elevation view of a driver tool of a fastening system forthe horizontal coil fastening system of FIG. 43;

FIG. 47 is a detail view of the horizontal coil fastening system base ofFIG. 43;

FIG. 48 is a side view of a closed metal loop fastening systemincorporated into a device;

FIG. 49 is a top view of device incorporating the closed metal loopfastening system of FIG. 48;

FIG. 50 is a side view of a two-part snap fit fastening system;

FIG. 51 is an elevation view of another closed metal loop system usingcurved pins or hooks;

FIG. 52 is a side view of the closed metal loop system using the curvedpins or hooks of FIG. 51 incorporated into a device;

FIG. 53 shows top and side views of a curved pin fastening systemincorporated into a device;

FIG. 54 shows top and side views of another curved pin fastening systemincorporated into a device;

FIG. 55 shows bottom and side views of a spring screw fastening system;

FIG. 56 shows side view of a folding baseplate with curved fasteners inits open and closed positions;

FIG. 57 shows top and side views of rotating hook fasteners incorporatedinto a device;

FIG. 58 is a top elevation view of a rotating disc fastening system withfasteners in pre-deployment position;

FIG. 59 is a bottom elevation view of the rotating disc fastening systemof FIG. 58 with fastener in post-deployment position;

FIG. 60 is a bottom view of the rotating disc fastening system of FIG.58 with fasteners in post-deployment position;

FIG. 61 is a side view of the rotating disc fastening system of FIG. 58with fasteners partially deployed;

FIG. 62 is an elevation view of the curved fastener of the rotating discfastening system of FIG. 58 showing the axis of rotation;

FIG. 63 is cutaway side view of a delivery system;

FIG. 64 is a side elevation view of a delivery system;

FIG. 65 is a top view of the actuator lever of the delivery system ofFIGS. 63 and 64;

FIG. 66 is a side view of the actuator lever of the delivery system ofFIGS. 63 and 64;

FIG. 67 is a bottom view of the actuator lever of the delivery system ofFIGS. 63 and 64;

FIG. 68 is a side elevation view of the actuator lever of the deliverysystem of FIGS. 63 and 64;

FIG. 69 is a partially exploded and cutaway view of the port cover ofthe delivery system of FIGS. 63 and 64;

FIG. 70 is a partial cutaway view of the port cover of the deliverysystem of FIGS. 63 and 64;

FIG. 71 is a back view of the port cover of the delivery system of FIGS.63 and 64;

FIG. 72 is an elevated side view of the port cover of the deliverysystem of FIGS. 63 and 64;

FIG. 73 is an elevated bottom view of a loading fixture;

FIG. 74 is a bottom view of a loading fixture;

FIG. 75 is an elevated view of a loading fixture;

FIG. 76 is an elevated view of a disc fastener/port/loading fixtureassembly; and

FIG. 77 is an exploded view of a disc fastener/loading fixture assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention encompasses surgical fastening systems wherein animplantable device either contains a plurality of fasteners (e.g.staples) in pre-deployment position, or wherein fasteners are providedadapted to suture holes on the device, or wherein an implantable devicemay have a detachable housing fitted over the device, wherein thehousing contains a plurality of fasteners in pre-deployment position.

The detachable housing and fasteners may be made of various materialsknown in the art for the manufacture of surgical fasteners and implants.The fasteners may be made of metal, polymer, or other suitablematerials. The detachable housing may be made of metal, polymer,ceramic, or composites; for instance polysulfone, acetyl copolymers,titanium, elastomers and stainless steel are commonly used.

These materials must be biocompatible, i.e., they do not adverselyaffect the surrounding living environment, and conversely, theirperformance is not adversely affected by the surrounding livingenvironment. The materials may be inert non-absorbable or biodegradable.Inert materials may be fairly indestructible and maintain their form andfunction for extended periods of time.

Metals and metal alloys, and particularly titanium and titanium alloys,are used for a great variety of implantable articles for medicalapplications. All implantable articles suffer from some degree ofbio-incompatibility, which may be manifested as tissue inflammation,necrosis, hyperplasia, mutagenicity, toxicity, and other reactions, suchas attack by giant cells, leukocytes and macrophages. While titanium andits alloys are generally considered inert when implanted, somebiological and biochemical interactions still may occur, and others havefound it desirable to provide various coatings on the surface oftitanium and titanium alloy implants for certain purposes. The sameholds true for many other metals and metal alloys. Thus, the presentinvention encompasses the use of such coatings on the surface of thefasteners, the removable housing, or the device.

Some of the coatings that may be used in materials to be implanted(whether made of titanium or other materials) include biological agents(such as genetic material or cellular material) or chemical agents (suchas anti-proliferation reagents or cell-growth factors) to reduceproblems associated with hyperplasia or inflammation. These agents maybe mixed with binders such as elastomers or bio-resorbable polymers tothe surface of a metal or polymer object.

The fasteners contemplated herein, including staples, are oftenconstructed of wire and thus have a relatively large surface area fortheir size. Accordingly, methods that allow the addition of biologicaland biochemical agents to the surface of the implant may be advantageousin minimizing the adverse reactions of body tissues with the implant.These may include coatings applied to stainless steel and titaniumalloys (e.g., NiTi alloys) to retard tissue reactions. Such coatingshave been based upon stable bio-compatible polymers (such asstyrene-isobutylene-styrene (SIBS)) and bio-resorbable polymers, such aspolyglycolic acid. In the work known to date, the active chemical orbiological agent is mixed with the polymeric coating material, and theagent then elutes from the coating once the implant is placed in thebody.

It is also contemplated by the present invention that the fasteners maybe made of shape memory alloy (SMA). The driving force for making metalmedical devices from shape memory alloys lies in their great resistanceto permanent deformation as compared to conventional alloys employed inthis application. Alloys used in various medical instruments have reliedon stainless steel, high nickel alloys such as Elgiloy™ and titaniumbased alloys, all of which can be given quite high yield strengththrough work hardening. Normal metals, even with very high yieldstrength, cannot sustain strains much greater than 0.2% withoutsuffering a permanent set. Once a bend or kink has been sustained in adevice fabricated from one of the above conventional alloys it isvirtually impossible to remove. The unusual property of pseudoelasticityexhibited by shape memory alloys such as Au—Cd, Cu—Zn—Al, Ni—Ti and manyothers makes possible the complete “elastic” recovery of strains asgreat as 10%. Due to its high recoverable strain and its excellentresistance to corrosion, the shape memory alloy of preference formedical components has been within the Ni—Ti family of alloys.

Shape memory alloys belong to a class which exhibit thermoelasticmartensite transformation. The term martensite refers to the crystallinephase which is produced in steels when quenched from a high temperature.The phase which exists at the elevated temperature is referred to asaustenite; these terms have been carried over to describe thetransformations which occur in shape memory alloys. When a steel hasbeen quenched from the austenitic temperature to martensite, to againform austenite requires heating the structure to quite hightemperatures, usually in excess of 1400° F.

By contrast, the thermoelastic shape memory alloys can change frommartensite to austenite and back again on heating and cooling over avery small temperature range, typically from 18 to 55° F. Thetransformation of a shape memory alloy is usually described by ahysteresis curve in which it is shown that on cooling from theaustenitic phase, often called the parent phase, martensite starts toform at a temperature designated as MS and upon reaching the lowertemperature, M_(F), the alloy is completely martensitic. Upon heatingfrom below the M_(F) temperature, the martensite starts to revert to theaustenitic structure at A_(S), and when the temperature designated asA_(F) is reached, the alloy is completely austenitic. These two phasesor crystalline structures have very different mechanical properties: theYoung's Modulus of austenite is ˜12×10⁶ psi, while that for martensiteis ˜4×10⁶ psi; and the yield strength, which depends on the amount ofcold work the alloy is given, ranges from 28 to 100 ksi for austeniteand from 10 to 20 ksi for martensite.

The unique feature of shape memory alloys is their ability to recoverdeformation. When a shape memory alloy specimen, in its martensitic formis subjected to stress, the strain is accommodated by the growth andshrinkage of individual martensite variants rather than by themechanisms which prevail in conventional alloys: slip, grain boundarysliding and dislocation motion. When deformed martensite is heated tothe austenite finish temperature A_(F), the part reverts to its originalundeformed state. Thus, for medical implant uses, it is possible todevelop a design where the device is stored below body temperature inits unformed shape, and upon insertion into the body, the temperature ofthe device raises to that of the body, at which point the device revertsto the austenitic structure. In the instant application, the fastenersmay be optionally made of an SMA such as NiTi.

It is within the scope of the present invention that such fasteningsystems as herein described are able to be fastened into bodily tissuein less time than would be required to suture the device into place. Inthe instance described here (the placement of an access port for agastric band), the placement and fixation of the fastening system shouldtake no more than five minutes. Additionally, the fixation system isable to be entirely unfastened and removed from the tissue in order tofacilitate repositioning of the device, or to remove the implanteddevice entirely. Such implantation and extraction will not causeincreased trauma to the patient, and the fixation system will not causemore adhesions than the traditional suturing method. The average surgeonor other health professional is reliably and consistently able toperform fixation and extraction of the fastening system.

Additionally, during the manufacture of such fixation systems describedherein, the size of the fasteners determines the depth into the bodilytissue into which the fasteners will deploy. In the instant case,fixation of an access port should occur at a depth below the device notto exceed 3 mm. Also, in such a use, the bodily tissue into which thefasteners are deployed is the fascia. However, it is within the scope ofthe invention that the bodily tissue to which the device is attachedwill vary depending on the specific device. Additionally, the attachmentof the fastening system into tissue will not cause tissue damage duringplacement or during body motion; for example, an access port for agastric band is often attached directly over the rectus abdominis.Further, the fixation of the device is of equivalent or greater strengthto sutures and resists becoming dislodged or disconnected in order toaccommodate a long-term implant.

The invention as described herein may be used with any type ofimplantable device. Examples of such would include internal monitors,ports, pacemakers, therapeutics, drug delivery systems,neurostimulators, orthopedic devices, tendon repair, etc. For ease ofexplanation, the invention will now be described as depicted in FIGS.1-40, wherein the invention is shown used in conjunction with an accessport. One of skill in the art will recognize that the present inventionmay be used with other types of implantable devices, and that theinvention may take other forms analogous to those depicted herein.

Additionally, in the accompanying figures, the housing is shaped as aring, and may accordingly be described as such. However, one of skill inthe art will recognize that the shape of the housing is dependent onthat of the device, such that the present invention is not limited todevices in which the housing would be circular.

FIG. 1 depicts an access port fastening system according to oneembodiment of the present invention. The access port 10 includes aseptum 11, which in practice is pierced by a needle to input fluid suchas saline into the access port for use with, for example, a hydraulicoperated gastric band.

The access port 10 includes a detachable housing 12 which surrounds theouter perimeter of the access port. The detachable housing 12 may be inthe form of a molded ring with a frusto-conical outer shape that snapsover an existing access port 10. The housing 12 includes notches oropenings 15. The notches house fasteners 14. The notches or openings 15may take any form necessary to adequately house the fastener 14 whileallowing movement of the fastener 14. It is within the scope of theinvention that at least three fasteners 14 be present in order tominimize the possibility of movement or dislodgement of the device. Asshown in FIGS. 1-4, the fasteners 14 are attached to the ring 12 by aperpendicular segment engaged through a hole and are thereby pivotallyconnected to the ring 12. The fasteners 14 have a first or pre-deployedposition as shown in FIGS. 1 and 3 and a second, deployed or securedposition as shown in FIGS. 2 and 4. To move from the first to the secondposition, the fastener rotates about an axis of the fastener, and in theillustrated embodiment the fastener pivots in a radial plane. The notch15 accommodates this rotation and a small locking tab 16 holds thefastener in position after rotation. In one embodiment, the fasteners 14may be 2-legged staples. In another embodiment, the staples are rigid,such that they do not deform during the rotation into the fascia of apatient. For such applications conventional metals are suitable.Furthermore, the staples may be shaped as a “U” or variations thereof,including substantially shaped as:

When in the second, deployed position, the fastener 14 is held rigidlyin place by a locking tab 16, and fastener 14 may flex to allow thefastener to pass into the locked position. The formation of the lockingtab 16 may be such that upon movement of the fastener 14 from the firstto the second position an audible click is heard by the surgeon toindicate that the fastener 14 is fully engaged by the locking tab 16.The click may also be tactile, allowing the surgeon to feel and confirmthrough the proximal handle that the fastener is fully engaged bylocking tab 16. When in the second position an access port 10 is securedwithin the housing 12 in the patient by the fasteners 14 which interfacewith the fascia of the patient. Essentially, the fascia or other bodilytissue is secured between the fasteners 14 and the housing 12 or device10. As seen in FIG. 2, tips of the fasteners 14 nest against a bottomsurface of the access port 10, in effect sandwiching the port betweenthe ring-shaped housing 12 and the fasteners. Furthermore, the housing12 may contain pegs (not shown) which engage suture holes (not shown)which surround the perimeter of the device 10.

FIGS. 5-8 depict the access port of FIG. 1 and its interaction with anaccess port delivery system 20. As shown in FIG. 5, the access portdelivery system 20 may have a finger depression 25 on the distal end ofa port cover 21 which is used by the operator to help hold the accessport and the delivery system in place at the delivery location, stableand properly aligned. The finger depression 25 allows for tactilepositioning and finger pressure can be applied to the top of the portcover distal end to increase placement confidence.

The delivery system 20 comprises a port cover 21 with a distal endhaving an open bottom that descends down over and captures the accessport 10, and a proximal portion that extends upward at an angletherefrom toward a handle. The port cover 21 houses a rod-like plunger22, a slide pusher 24, and a slide assembly 26, as seen in FIG. 6. Theport cover may be formed in any shape necessary to substantially coverthe access port 10, and in the illustrated embodiment has afrusto-conical distal end that conforms over the housing 12. Thedelivery system 20 interacts with a number of different proximal handleconfigurations, such as shown in FIGS. 9-19.

The plunger 22 provides the operative means for the delivery system 20and is connected to a firing means which will be described below. Uponactuation of the firing means the plunger 22 moves in the direction ofthe access port 10 which, as illustrated in FIG. 6, is downward at anangle to the vertical. This movement causes the slide pusher 24 to beactuated. The slide pusher 24 transfers the energy of the moving plunger22 to the slide assembly 26. The slide pusher 24 is wedge-shaped as seenbest in FIG. 7 so as to cam and deliver downward force to the slideassembly 26 as it slides across the top surface thereof. The slideassembly 26 has a substantially round shape and encircles the accessport 10. As seen in FIG. 7, a series of elongated beams 28 spaced aroundthe periphery of the slide assembly 26 extend downward into the notches15 in the housing 12 and contact the fasteners 14 therein. In otherapplications, the slide assembly may take a form suitable to the deviceand housing to be implanted. Upon actuation, the slide assembly 26 isforced in the direction of the access port 10. Alignment tabs 30 as seenfrom below in FIG. 8 assist the alignment of the slide assembly 26. Thealignment tabs 30 are attached to the port cover 21 and interact withthe access port 10 to ensure proper alignment. The movement of the slideassembly 26 causes beams 28 attached to the slide assembly 26 to actupon the fasteners 14. The imparting of force on the fasteners 14 allowsthem to rotate in the ring holes (not shown) and to transcribe an arcdefined substantially by the notch 15. This rotation coincides with amovement from the first to the second position discussed above. As thebeams 28 continue to be moved towards the access port 10, the fasteners14 are forced past the locking tabs 16 into tissue below the access port10 to reach the second position, and are held in place by the lockingtabs 16. In this position, with the fasteners 14 deployed as seen inFIG. 8, the access port 10 is rigidly held in place by the fasteners 14and their interaction with the fascia or other tissue of the patient. Atthis stage the port cover 21 may be retracted upward from around theaccess port 10. A feature on the port cover 21 captures the access port10 therein until deployment is complete, at which time the port isreleased.

FIG. 9 shows an access port delivery system complete with a firing means40 in a pencil-grip style handle attached to the proximal end of theupwardly angled shaft of the delivery system 20, which is shown at 60°from the horizontal. FIG. 10 shows a cross sectional view of the firingmeans 40 in the starting or loaded position. In this position, thespring 42 is compressed, and a latch 44 that is connected to a rod 46 onthe proximal end of the plunger 22 is secured by a rib 48 to prevent thecompressed spring 42 from expanding. The firing means has a button ortrigger 50 connected to a lever 52. As shown in FIG. 10 the spring 42and rod 46 are in a housing 54.

As shown in the fired position of FIG. 11, upon application of apredetermined force to the trigger 50, the lever 52 acts on the housing54. The housing 54 pivots on a fulcrum (not shown), this pivoting actionlifts the latch 44 above the end of the rib 48, thus dislodging the rod46 and allowing it to advance distally. Upon lifting, the spring forceof the compressed spring 42 drives the plunger 22 in the direction ofthe access port and actuates the mechanism therearound as discussedabove. In such a configuration the plunger travel, speed and impactforce can be determined to meet the application needs. As tested, theplunger travel was between 0.25 and 0.75 in, and can develop up to 50lb. of force on the plunger, depending upon the spring used in theapplication. Deployment of the plunger 22 is thus instantaneous with ahigh impact speed, though a slower deployment mechanism controlled bythe surgeon may be provided.

An alternative handle configuration to the spring driven mechanismdescribed above is shown in FIG. 12. FIG. 12 shows a palm grip actuatedfiring mechanism 60. The palm grip is a very simple lever designrequiring only a single moving part to move the plunger 22. In a firstor starting position as shown in FIG. 13, there is a moving handle 61(or lever), a stationary handle 62 (or housing), a pivot point 64, andan actuating tip 66. The handle is oriented generally horizontally andattaches to the upwardly-angled shaft of the delivery system 20, whichis shown at 60° from the horizontal.

In operation the user squeezes on the moving handle 61 forcing it in thedirection of the stationary handle 62 to the fired position of FIG. 14.This movement forces the actuating tip 66 which is connectively engagedwith the moving handle 61 and the pivot point 64 in a direction oppositethe direction of movement of the movable handle 61. Through the use ofthe simple lever action, a comparatively small force applied to themoving handle 61 (lever) is amplified through the pivot point 64 andapplied by the actuating tip 66 to the rod-like plunger 22. The plunger22 is moved downward at an angle by the actuating tip 66 in thedirection of the access port 10 and actuates the mechanism therearoundas discussed above. The force produced by the palm grip actuated deviceis limited only by the strength of the user, as tested the device wascapable of producing in excess of 50 lb. of force with a plunger travelof 0.25 in. Deployment speed is controlled by the operator.Alternatively, a geared mechanism could be produced that could produceequal or greater force although require a greater travel distance forthe moving handle 61. The force produced by the device shown in FIGS.12-14 could also be altered as necessary by moving the pivot point 64nearer the plunger 22 to produce more force, or away from the pivotpoint to produce less force.

Yet another alternative firing means/handle configuration is shown inFIGS. 15-19. The pistol grip firing means 70 includes a trigger 72having geared teeth 73 located on one end, a gear 74 which meshes withthe geared teeth 73, a rack 75 driven by the gear 74, and a spring 76.The rack may also include a means 78 for gripping the plunger 22, whichis slip fit within the delivery system 20 shaft.

The operative progression is shown in FIGS. 17-19. In the startingposition of FIG. 17, the trigger is extended and the spring is underlittle or no tension. The geared teeth 73 are meshed with correspondingteeth of the gear 74 and with teeth on the rack 75. The plunger 22 is inthe extended position. When the trigger 72 is depressed, the gearedteeth 73 actuate the gear 74 and in turn cause the rack 75 to compressthe spring 76 into the full spring recoil position, as shown in FIG. 18.At a predetermined distance the geared teeth 73 no longer engage thegear 74. At this point the gear 74 is free to spin. The stored energy inthe spring 76 forces the rack 75 to move toward the plunger 22. The freespinning gear 74 allows the rack 75 to move, which in turn forces therod-like plunger towards the access port 10 and actuates the mechanismtherearound as discussed above, and as seen in the fired position ofFIG. 19.

Another feature which may be incorporated into the pistol grip firingmeans 70 is a lock (not shown), which after the spring 76 is compressedprevents the gear 74 from spinning. Then when desired the operator canrelease the lock, thereby allowing the spring 76 to expand as discussedabove.

As tested, the pistol grip firing means 70 permits the plunger to travelapproximately 0.4 in and can produce in excess of 50 lb. of force. Onedistinct advantage of this embodiment over, for example, the movablegrip device discussed above is the instantaneous deployment having avery high impact speed.

In FIG. 20 a further embodiment of the present invention is shown. Theuse of NiTi (Nitinol) or SMA alloy materials is well known in themedical arts as discussed above. As shown in FIG. 20 NiTi fasteners areshown in a pre-deployment state. The fasteners 14 are arranged in acontinuous wireform with legs attached to the access port 10 throughholes therein. In operation the fasteners 14 are depressed into thefascia of the patient to secure the access port. The NiTi fasteners 14have the unique ability to change their shape when heated, e.g. to bodytemperature. As shown in a post-deployment state in FIG. 21, when thefasteners are deployed they can change shape to bend under and towardsthe center of the access port 10 and secure it in place.

In FIG. 22 the fasteners 14 are shown with straight legs 80 parallel toa base of the access port 10 in a deployed state. Alternativeconfigurations include curved legs 81 as shown in FIG. 23. By virtue ofthe continuous wireform, the fasteners/legs are formed by narrowclosed-loop projections with blunt tips. Using the curved legs 81 whichtrack into the base of the access port 10, the fascia can be pinchedbetween the fastener and the underside of the access port. A furtheralternative is shown in FIG. 24 where the tips of the continuouswireform fastener legs 81 are coated with a molded tip 82. The moldedtip may be formed in a shape that will assist in piercing the fascia ofthe patient. This eliminates the need to form the fastener 14 into ashape for piercing. Additionally, the tips 82 may be formed of abio-absorbable material.

In another embodiment of the present invention, the NiTi fastener can becontinuously formed as one-piece along with an insert-molded ring 84, asin FIGS. 25-27. The use of the ring 84 allows for the NiTi fasteners 14to be formed with a continuous one-piece construction. After theinsert-molded ring 84 with the fasteners 14 is formed, the ends of thelegs 80 can be ground off to produce individual substantially U-shapedfasteners 14. The ring 84 insures that the fasteners 14 can be insertedas a unit as discussed above, and the grinding of the legs ensures asufficiently sharp point to more easily pierce the fascia. As shown inFIGS. 25 and 27, the legs can be formed and positioned in the ring 84 sothat after bending due to heating, the legs 80 face internally to theaccess port 10 or externally to the access port 10.

Yet another embodiment of the present invention is a two-part radialslide fastening system as shown in FIGS. 28-34. FIG. 28 shows a guide 90formed with a plurality of individual fasteners 14. The guide 90 may bea molded circular flange-like member as shown. The fasteners 14 areslidable in the guide 90 from a first to a radially inward secondposition. In operation the guide 90 is placed over the access port 10and aligned with notches 15. The fasteners 14 are formed of a springlike material and shaped to attach to the access port 10. The fasteners14 are slid from a first position as shown in FIG. 28 to a secondposition as shown in FIG. 29. Small protrusions on each fastener 14 maysnap into place in suture holes of the access port 10, as seen in FIG.29. The fasteners 14 pierce the fascia and securely hold the access port14 thereto. As previously described, the fasteners may have straight orcurved legs, the former shown in FIGS. 28 and 29 and the latter in FIG.30. After the sliding of all of the fasteners from the guide 90 onto theaccess port 10, the guide may be removed if it is not part of the finalimplanted device. Alternatively, the guide 90 may also be a permanentpart of the implantable device.

A further two-part fastening device includes a pre-formed ring 100 (FIG.31 and FIG. 32). The ring includes a first securing means 104 forattaching the ring 100 to the fascia. The ring also includes a secondsecuring means 102 for attaching an access port 10 to a secured ring100. In operation, the ring 100 is placed upon the fascia and thentwisted to engage the fascia in the first securing means 104. The accessport 10 is then placed upon the ring 100 and engages the second securingmeans 102 via holes 106 in the access port. This design allows forpositive attachment and re-installation repeatability withoutdisengaging the pre-formed ring.

FIG. 33 and FIG. 34 depict pre- and post-installation stages,respectively, for yet another two-part fastening device comprising anapplicator 112 and a ring 110 having NiTi fasteners 114. In practice,the ring 110 is inserted into the applicator 112. The applicator 112 isplaced over the access port 10 with the fasteners 114 aligned withnotches 115 and holes 106. The fasteners 114 are forced through theholes 106 and engage the fascia of the patient upon which the accessport 10 rests. Through the heating process, the fasteners 114 changeshape and secure the access port to the fascia. After a predeterminedtime, the applicator can be removed.

Another embodiment of the present invention regards stand alonefasteners. As shown in FIGS. 35-38, a variety of designs can be used tosecure an access port 10 to the fascia of a patient. The fasteners mayincorporate NiTi so that the fasteners change shape upon application ofa predetermined amount of heat. These fasteners 14 may be insertedsingularly, or as part of a pre-formed ring as discussed above. Wheninserted singularly, the fasteners 14 may be straight rods or may havesome pre-formed shape which may be heightened through the heatingprocess. In FIG. 35, the fastener 14 takes on a curly, pig-tail shape.In FIG. 36 the fastener takes on a substantially C-shaped appearance.FIGS. 37 and 38 use U-shaped fasteners 14, the ends of which bend,linearly when heated to form an omega shape as shown in FIG. 37, orperpendicularly to the shape as shown in FIG. 38. These shapes can bechosen as desired for a specific application.

Yet another embodiment of the present invention is shown in FIG. 39. InFIG. 39 the fasteners 14 are slidably installed in the access port 10.This may be accomplished by cold molding of the NiTi fastening systeminto the device, and allows positive attachment and repeatablere-positioning. Through the use of an installation tool 120, thefasteners are forced through holes in the bottom of the access port 10and engage the fascia. By installing the fasteners as an integral partof the access port 10, no ring or housing is needed as discussed abovefor housing the fasteners. The installation tool 120 could be part of atriggering device as disclosed herein. FIG. 39 is a pre-installationstage and FIG. 40 shows the fastener 14 in the engaged position.

As described above and shown in FIGS. 1-8, radial pivot fasteners are asimple delivery system, with direct drive. The associated deliverysystem actuates the pivot for radial entry. The staple may be stainlesssteel, titanium, Nitinol or Elgiloy™, or other suitable materialsincluding other metals or plastics. The molded pivot/lock-out system maybe designed to snap into the existing suture holes on implantabledevices. Additionally, the simple staple shape allows for easymanufacturability. Such a system is self-puncturing, i.e. nopre-puncturing of the bodily tissue, e.g. fascia, is necessary. Thecurved nature of the staple allows the penetration into the bodilytissue as the staple advances to be predictable; and the pivoting natureof the curved staple generates an easy path through the tissue. Removalof the fastening system requires an extraction tool, and the stapleswill rotate out of the original entry path with only small resistancefrom ingrown surrounding tissue. However, the force required to removethe system is adequate to allow the staples to remain locked in positionexcept during a removal procedure.

Continuous wire forms of the fastener system contemplated herein includeblunt tips, molded tips, and ground or chopped tips. Blunt tipcontinuous wire systems, as shown in FIGS. 20-23 may requirepre-puncture for insertion of the blunt tipped wire. The fastenerassembly may be manufactured to require the locking feature to retaineither the wire form or the overmolded ring. The simple wire form may bemade of stainless steel, titanium, Elgiloy™, NiTi or other suitablematerials. Removal of the fastener assembly may be done easily due tothe blunt ends, which provide minimal tissue damage and trauma.Additionally, the blunt tip reduces the force necessary to remove theassembly. The continuous wire form assembly with molded tips, shown inFIGS. 20 and 24, does not require pre-puncture of the bodily tissue, andthese tips allow for easy entry into the bodily tissue. Further, thechopped or ground blunt end continuous wire form assembly, FIGS. 25-27,also requires no pre-puncture of the bodily tissue, which also allowsfor easy entry into the tissue.

The radial slide fastener assembly, depicted herein with flat fasteners(FIGS. 28 and 29) and curved fasteners (FIG. 30), requires a largerentry site than the other fastener assemblies. The fasteners create apath through the bodily tissue that is simple and secure, with addedretention in systems utilizing the curved fasteners. Removal of thesystems is accomplished with an associated extraction tool thatwithdraws each fastener from their center position. Alternatively, thefasteners may be manufactured such that removal may be accomplished bylifting the assembly upwards, at which time the fasteners bend to astraightened position, allowing for easy removal.

FIG. 41 depicts a helical coil fastener 201, which may optionally beutilized with a port that features a tubing connector extending from thecenter of the base. The corkscrew-type design is mounted to a separatedisc 203 which snaps to the port at tabs 202, or alternatively, may bemounted to the port itself, centered on the base plate. The disc or portis manually affixed to the tissue by rotation of the disc or port, whichcauses the coil to travel on a helical path through the tissue. In oneembodiment, the coil can have a sharpened tip.

A variation of the helical coil fastener is depicted in FIG. 42. FIG. 42depicts a flat spiral spring 204 that is deflected downward to begin itspath through the tissue. The deflecting implement 205 may be withdrawnfollowing implantation, allowing the spring to compress during healing.Compression of the spring will reduce the profile of the implanted coilfastener and can reduce the likelihood of pain induction. Tabs 202 areused for locking a port or other device into the fastener.

FIGS. 43-47 and FIG. 55 depict a horizontal coil implantation system. Inthe horizontal coil system, a metal coil is used horizontally to stitchthe port to the tissue. It is well known that such coils can pierce andhold in tissues from their use as mesh tacks in minimally invasivehernia procedures. In this case, the coil travels parallel to the tissuesurface instead of perpendicularly, as in the helical coil fastenersdescribed above (see FIG. 55). One example of such a coil is formed of0.014 inch D wire having a pitch of 0.0100 inch. A small deployment tool206 with a slotted driver is envisioned to aid in driving the coil 208through the tissue and the mating holes 207 in the base coil receptacle209 (see FIGS. 46 and 47). Such holes could be straight holes through aridge on the bottom of the base (see FIGS. 44, 45 and 47), or curvedholes molded into a flat-surfaced base. The coil holes shown in FIG. 47are shown spaced apart 0.100 inch, the same as the coil pitch, andhaving a diameter of 0.240 inch. A top view of a base is shown in FIG.43. It is envisioned that the last hole would be blind, and that the endof the coil would be shaped in a crossbar that could slide over anincline and lock into place, such as into a slot. Desirably, a solidstop for advancement of the coil is provided, and there may be a latchconfiguration wherein the driver end of the coil catches on theunderside of the base. A variation would feature a path for the coilthat curves around the port or base edge, facilitating tool access tothe coil. This can also be accomplished by varying the flexibility ofthe coil. A tube can be added to the tool as a shroud in order to keepthe rotating coil from picking up strings of tissue before it travelsthrough the holes.

FIGS. 48 to 62 depict various embodiments of a metal suture system. Thismethod of port fixation involves the creation of one or multiple closedmetal loops below the port base, by using the base itself as a means toclose a loop formed by curved metal members 211 (see, e.g. FIGS. 48 and52). FIG. 48 illustrates one closed loop, with a single curved metalmember shown in its post-deployment position. FIG. 49 is a cutaway topview of one embodiment of the invention showing the curved metal members211 in their pre-deployment position. FIG. 57 depicts both a bottom andside view of one embodiment of the invention showing the curved metalmembers forming a loop with the bottom of the base. FIG. 51 shows curvedmetal members, with the arrows indicating their deployment rotation.Fastening of a port in the above described manner may be done both withone-piece and two-piece systems, whereby a two-piece system may have aring 210 that attaches to the port or other device by snap-fitting withtabs 202 as shown in FIG. 50. One embodiment includes a deflection toolto separate the point of the metal member from contact with the baseallowing the member tip to begin its path downward through the tissue.This can be a circular disc or the port itself. After the point hastraveled some distance, the tool is withdrawn, permitting the curvedmember to then follow a path intersecting with the base. Likewise,another embodiment includes multiple members curved in two planes, suchthat rotation of the base affects the creating of multiple loops.

An alternate method to achieve such a loop is with a curved pin 212(hook or needle) that is inserted through the base after it is in itsintended tissue location, as seen in FIGS. 53 and 54. Such a pin bynature follows an arc through the tissue and can easily be directed backto the port base. Such a pin can be made to lock in place after fulltravel by adding a right angle bend 213 to the pin that snaps into aslot 214 on the base, or other such well-known means. A variation onthis theme includes an additional straight section on the end of thepin, parallel to the curved section. A lever arm 215 is used to drivethe curved section through the base and to the completion of itsintended travel.

In yet another embodiment, a two-piece system may be used wherein theport attaches to a folding baseplate 218 with sharp, curved extensions217 (see FIG. 56). The folded plate is placed on the tissue with theextensions pointed toward the tissue. When the baseplate is unfolded(flattened) the extensions are driven 90 degrees in a rotary path (seeFIG. 56). The port is then snapped to the baseplate, locking theextensions in position. In one embodiment, the points of the extensionswould overlap or cross over those from the other half, semi-shieldingthe points.

FIGS. 58-62 illustrate a preferred rotating disc fastener system. Afterbeing placed in its desired location, the device to be implanted issecured to the tissue using a plurality of curved pins or hooks 501(FIG. 62), the tips of which rotate through an arc and are received backin or near the baseplate 510 at the end of their travel. A disc 520within the baseplate 510 rotates, thereby causing lever arms 525 to pushagainst curved hooks 501, which in turn rotate about their fixed axis inthe baseplate through an arc until the rotational travel of the discstops. In the fully deployed position (FIGS. 59 and 60), the tips ofhooks 501 are preferably received back in baseplate 510 to form a closedloop. Alternatively, the tips may form less than a closed loop. Ineither case, it is preferable that the rotating disc 520 locks in placeat the end of its travel to lock the hooks in place. One-way flexiblelocking tabs 527 that engage stops 515 or other locking means may beused to lock the hooks in place by preventing backward rotation of thedisc. A deployment tool or delivery system such as that described abovewith reference to FIGS. 5-19 may be used to fasten the device in place.The linear motion of the plunger 22 and slide pusher 24 is convertedinto rotational motion through a transmission using gearing or otherwell known means.

FIGS. 63-72 illustrate a preferred access port delivery system.Referring to FIG. 63, which shows the port delivery system inpre-deployment position, lever 605 is attached to handle 607 at hinge621. Cable sheath 619 is secured to handle 607 by securing pin 623.Cable sheath 619 encloses cable 617 which is attached to lever 605 atthe handle end of the device at cable stop 615. Cable sheath 619 allowsthe linear motion of cable 617. At the deployment end, cable 617 isattached to actuator lever 701, which is snapped into port cover 631. Ascan be seen from FIGS. 66 and 70, actuator lever 701 and port cover 631have curved lips 721 for gripping the baseplate of a disc fastener.Additionally, actuator lever 701 has groove 723 to allow the actuatorlever to rotate around the baseplate with minimal contact, the onlycontact being from curved lip 721. FIG. 66 shows edge 713 of theactuator lever, which snaps into a matching groove of port cover 631 andsecures the actuator lever but allows its rotational motion. FIG. 65shows a top view of the actuator lever, and shows cable stop 705, wherethe deployment end of cable 617 is attached. Cable 617 runs through slot707 and out through notch 709 and along groove 711. When the user of thedeployment tool pulls lever 605 towards handle 607, cable 617 is pulledthrough the sheath towards handle 607. As the cable is pulled throughthe sheath, it pulls the actuator lever at cable stop 705, causing theactuator lever to rotate along the path prescribed by edge 713 and itscorresponding groove in port cover 631. FIGS. 69 and 70 show partiallyexploded and cutaway detail of the various parts of the actuator lever,port cover and cable assembly. Thus the linear motion of cable 607 isconverted to the rotational motion necessary to deploy the fasteningsystem.

FIGS. 71 and 72 show an embodiment of port cover 631 in greater detail.Attachment position 735 is the location where a cable sheath may attachto the port cover. In addition, both FIGS. 71 and 72 show devicepassageway 737. Device passageway 737 allows a port cover to be attachedto a port or other device without interfering with any tubing or otherinstrumentation that may be running from the port or device. In thisembodiment the passageway is a square shape, however the passageway maybe in a wide variety of shapes to accommodate a variety of devices.

FIGS. 73-77 depict a loading fixture 730 for holding a combinedport/disc fastener assembly. The port/disc fastener system is snappedinto the fixture, which protects the assembly, protects the user fromaccidental contact with the hooks, sharpened points, etc., used tofasten the assembly to tissue, prevents premature deployment of theassembly, and allows the user to load the port/disc fastener system intothe deployment tool without actually touching the assembly. Thedeployment tool is snapped onto the assembly while it is still in theloading fixture 730. Similar to the device passageway of the port cover,the loading fixture has device passageway 739 to allow any tubing tohang freely from the device to be attached without any interference fromthe loading fixture. FIG. 75 shows how a device may be securely held inplace by locking tabs 743 and/or pegs 741. FIG. 76 shows a port/discfastener assembly being held securely by the loading fixture. FIG. 77shows an exploded view of the disc fastener/loading fixture assemblywithout a port device 10 attached.

A brief description of the combined use of preferred embodiment of thedisc fastener system shown in FIGS. 58-62, the preferred embodiment ofthe deployment tool of FIGS. 63-68 and the loading fixture of FIGS.73-77 is helpful in understanding the invention. The user grasps theport delivery system at handle 607. The port/disc fastener assemblywould be held in the loading fixture, as shown in FIG. 76. The usermaneuvers the port cover 631 over the port/disc fastener assembly, andcurved lips 721 of the actuator lever and port cover snap-fit with thebaseplate 510, such that an audible and tactile click is heard and feltby the user. The user then pulls the deployment tool from the loadingfixture with the combined port/disc fastener attached and ready to bedeployed. The user then positions the combined port/disc fastener systemsuch that the disc fastener is set in its location for deployment. Oncein place, the user pulls the lever, setting the actuator lever inmotion. Actuation edge 725 engages with a single lever arm 525, rotatingthe lever arms until the fasteners are fully deployed. Upon fulldeployment an audible and tactile click is both heard and felt by theuser, as the port is ejected from the port delivery system, and thedeployment is complete.

Although the invention has been particularly shown and described withreference to certain preferred embodiments, and in particular withreference to an access or injection port, it will be readily appreciatedby those of ordinary skill in the art that any number of implantablemedical devices may be used with the fastening system of the presentinvention and that various changes and modifications may be made thereinwithout departing from the spirit and scope of the invention.

1. An implantable injection port, comprising: a housing defining aperiphery and having an upper face generally oriented in a planeperpendicular to a vertical axis; a septum within the housing open tothe upper face and capable of penetration by a needle along the verticalaxis; a space below the septum defining a fluid reservoir; a tubingconnector extending out of the housing from the periphery in fluidcommunication with the reservoir; and a sharp-tipped fastener attachedto the housing and mounted to pivot from an undeployed position withinthe housing periphery and not projecting below a lower face of the portopposite the upper face to a deployed position projecting below thelower face of the port to pierce tissue and enable a user to attach theport to tissue without sutures.
 2. The port of claim 1, wherein thereare a plurality of the fasteners in the form of curved hooks distributedaround the lower face of the port that each pivot from their undeployedpositions to their deployed positions.
 3. The port of claim 2, whereinsharp tips of the curved hooks pivot through an arc and are receivedback in or near the lower face of the port at the end of their travel.4. The port of claim 2, wherein the hooks pivot about axes that aregenerally radially oriented outward from a center at the vertical axis.5. The port of claim 2, wherein the hooks pivot about axes that aregenerally tangential to a circle with a center at the vertical axis. 6.The port of claim 2, wherein there are at least three hooks.
 7. Animplantable injection port, comprising: a housing having an upper facegenerally oriented in a plane perpendicular to a vertical axis; a septumwithin the housing open to the upper face and capable of penetration bya needle along the vertical axis; a space below the septum defining afluid reservoir; a tubing connector extending out of the housing influid communication with the reservoir; and a plurality of curved hooksattached to the housing and distributed around a lower face of the portopposite the upper face, each hook mounted to pivot from an undeployedposition not projecting below the lower face of the port to a deployedposition projecting below the lower face of the port to pierce tissueand enable a user to attach the port to tissue without sutures.
 8. Theport of claim 7, wherein sharp tips of the curved hooks pivot through anarc and are received back in or near the lower face of the port at theend of their travel.
 9. The port of claim 7, wherein the hooks pivotabout axes that are generally radially oriented outward from a center atthe vertical axis.
 10. The port of claim 7, wherein the hooks pivotabout axes that are generally tangential to a circle with a center atthe vertical axis.
 11. The port of claim 7, wherein there are at leastthree hooks.
 12. The port of claim 7, wherein each hook produces anaudible click indicating that the hook has pivoted completely to thedeployed position.
 13. An implantable injection port, comprising: ahousing having a generally circular periphery defining a central axisand an upper face; a septum within the housing open to the upper faceand capable of penetration by a needle along the central axis; a spacebelow the septum defining a fluid reservoir; a tubing connectorextending radially out of the housing in fluid communication with thereservoir; and a plurality of curved metal fasteners attached to thehousing and distributed circumferentially around a lower face of theport opposite the upper face, each fastener mounted to pivot about anaxis that is generally radially oriented outward from the central axisfrom an undeployed position not projecting below the lower face of thehousing to a deployed position projecting below the lower face of thehousing to pierce tissue and enable a user to attach the port to tissuewithout sutures.
 14. The port of claim 13, wherein distal tips of thefasteners pivot through an arc and are received back in or near thelower face of the port at the end of their travel.
 15. The port of claim13, wherein there are at least three fasteners.
 16. The port of claim13, wherein each fastener produces an audible click indicating that thefastener has pivoted completely to the deployed position.